Torque transmitting tools with a drive element having a drive stud configured for detachable coupling to a tool attachment such as a socket have in the past been provided with mechanisms that allow an operator to select between an engaging position, in which the tool attachment is secured to the drive stud and accidental detachment is substantially prevented, and a releasing position, in which forces tending to retain the tool attachment on the drive stud are reduced or eliminated.
In the tools described in U.S. Pat. No. 5,911,800, assigned to the assignee of the present invention, a releasing spring 50 biases a locking pin 24 upwardly to a release position, while an engaging spring 48 of greater spring force biases the locking pin 24 downwardly to an engaging position (see, for example, FIGS. 1, 3, and 4; col. 3, line 66 to col. 4, line 20; col. 4, lines 49-59). By moving a collar 34 away from the drive stud end of the tool, the engaging spring 48 is manually compressed, thereby allowing the releasing spring 50 to move the locking pin 24 to a releasing position.
U.S. Pat. No. 8,024,997, assigned to the assignee of the present invention, shows a coupling mechanism with a biasing element or an engaging spring 62 that bears on a guided element 30 to bias the guided element toward an engaging element 18. It is described that the guided element may be shorter in the longitudinal direction to provide a longitudinally compact mechanism. While such a construction of the guided element allows a shorter axial construction of the mechanism, at least one of the guided element and the biasing element may tend to become skewed within the guide as a result of movement of the engaging spring 62 with the guided element.
The guided element of the present invention solves that and other problems by providing a guided element that at least partially overlaps the biasing element along the longitudinal axis. By providing such a construction of the guided element, any tendency for the guided element or biasing element to become skewed within the guide is minimized, if not entirely prevented. In addition, movement of the biasing element with respect to the guided element is constrained by the construction of the guided element according to the present invention.
Advantageously, a structure according to the present invention permits achieving a maximizing of the force exerted by the biasing element on the guided element while minimizing the length of the mechanism. It is possible therefore, to provide a greater biasing effect in a shorter space.